The Department of Radiation Oncology at the University of North Carolina, in conjunction with radiation oncology facilities at Rex Hospital in Raleigh, NC and Cape Fear Valley Medical Center in Fayetteville, NC propose to work with a newly formed cooperative group to perform a dose escalation study in carcinoma of the prostate utilizing 3D treatment planning techniques. We will utilize a 3D treatment planning system that has been developed at UNC to perform the treatment planning on all patients at UNC although the treatments on patients coming from the affiliated institutions will have the radiation therapy delivered at the affiliate. We project that we will accrue patients from a patient base of approximately 200 new patients each year with localized prostate cancer treated with radiation therapy. Depending on the details of the protocol developed by the cooperative group, we expect to be able to enter approximately 75 patients per year on study. Our treatment planning system allows full 3D planning capabilities with beams eye views generated for field definition along with digitally reconstructed radiographs with structure overlay. Doses are calculated using full 3D information with tissue heterogeneity correction and with dose-volume histograms available. Specialized tools which have been developed at UNC using a common computer platform of the NCI Tools Contract Working Group will be made available to the cooperative group. We will participate fully in protocol development with a planned dose escalation scheme which would start at a dose of 7020 cGy with 2 dose escalations of 540 cGy each. Patients will be carefully monitored for toxicity with dose escalation performed when an appropriate number of patients (as determined by the statistical center) have been observed for a long enough time to assure that excessive toxicity will not occur. We will send full dose/volume information to the statistical and operations center using agreed upon magnetic tape data exchange formats. Lastly, if the results of the dose escalation study suggest a possible benefit of this approach, we will work to develop a Phase III study of high dose conformal radiation therapy compared to lower dose radiation therapy.